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KevinW
 
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Default Increaseing Precision in polynomial trendline equations


I tried to re-create the example at;

http://www.stfx.ca/people/bliengme/E...Polynomial.htm

Here is the equation I used (using the 'array enter' crtl-shft-rtrn);

=LINEST(B2:B5,A2:A5^{1,2,3},TRUE,TRUE)

and here is the matrix result;

x3 x2 x b
2.166666667 2 148.8333333 -152.3333333
0 0 0 0
1 0 N/A N/A
0 0 N/A N/A
14105 0 N/A N/A


Excel's automatic trendline seems to work fine, correctly identifying
the equation as y = 2x^3 + 3x^2 - 6x + 8

I can't figure out why it won't work correctly. Am I missing something
simple? Do I need to change a preference setting I don't know about?

Thanks
Kevin


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